Charge pumping through isolated dopant atoms

Recently, a new kind of quantised charge pumping has been demonstrated (see G. C. Tettamanzi et al, 2014 New J. Phys., 16 063036) by using a single dopant atom quantised charge pump (SDA-QCP). The characteristics of the SDA-QCP were found to be quite different from the more conventional quantum dot charge pumps (QD-QCPs). This difference originates from the intrinsic dissimilarity in the confinement potential that traps the electrons during the pumping cycle and results in a lower non-adiabatic excitation error rate for the SDA-QCP. Here the experimentally determined performance of the SDA-QCP is compared to a new model that describes the behaviour in terms of frequency, power and the position of the dopant in the channel.